Answer:
the l sign means the substance in the chemical equation is a liquid. (hope this helped : D )
The electron configuration that represent an excited state for an atom of calcium is 2, 8, 7, 3.
Calcium atom has an atomic number of 20 and its electronic configuration is 2, 8, 8, 2. An atom is said to be in an excited state if it gains energy and move to an higher energy level. For the calcium atom given above, there are 20 electrons which are distributed into four shells. But in the excited state [option 3], one of the 8 electrons in the third shell gains energy and move to the fourth shell. Thus, the number of electrons in the third shell reduced by 1, while the number of electrons in the fourth shell increase by 1.
Answer: colloid
Explanation:
Colloids are solutions in which small sized particles are suspended throughout the solution as they do not settle own their own. Colloids are defined as the mixtures where the size of the particle is within the range of 2nm to 1000 nm. In these mixtures, physical boundary is seen between the dispersed phase and dispersed medium.
Colloids are solutions with particle size intermediate between true solutions and suspensions. Suspensions have large sized particles which settle when left undisturbed for sometime and thus can be filtered off easily. The particle size in colloids is less and hence they do not settle under the effect of gravity.
An isotope is when a normal atom has too many neutrons and its weight has been offset.